Sparganosis

Sparganosis is a parasitic infection caused by the plerocercoid larvae, or spargana, of cestodes in the genus Spirometra. In humans, sparganosis is an uncommon, accidental infection in which the larvae migrate through various tissues and may persist for years. The adult tapeworms inhabit the intestines of definitive hosts such as cats and dogs, while humans act as incidental intermediate hosts.

The life cycle involves eggs released in feces, which hatch into coracidia in freshwater. Copepods (the first intermediate hosts) consume the coracidia and develop into procercoids. Second intermediate hosts—such as fish, frogs, reptiles, and snakes—acquire the larvae by feeding on infected copepods, and the larvae mature to plerocercoids in their tissues. Humans become infected by ingesting raw or undercooked flesh of second intermediate hosts, by drinking water containing infected copepods, or by applying raw flesh as poultices to wounds or eyes.

Clinical features vary by location of the sparganum. Subcutaneous sparganosis presents as migrating nodules or plaques under the skin; ocular sparganosis can involve the eyelids, conjunctiva, or orbit and may threaten vision. Neurospganosis, including cerebral or spinal involvement, can cause headache, seizures, or focal neurologic deficits. Eosinophilia may be present; serology and imaging aid diagnosis. Definitive diagnosis is often achieved by surgical removal and examination of the larva.

Treatment centers on removing the larva when feasible, with mixed results from antiparasitic drugs such as praziquantel or albendazole. Prevention focuses on avoiding consumption of raw or undercooked Leporidae? No. Avoid raw or undercooked flesh of snakes, frogs, or fish; do not use raw animal flesh as poultices; ensure safe drinking water.